This invention relates to the manufacture of short lengths of pipe, such as are used in the assembly of manhole sections, on vertical pipe-making machines.
The high initial cost of these machines is justified by their large productive capacity. It is found, however, that the time to make a shorter pipe is only slightly less than to make a long pipe and although some manufacturers do use the vertical pipe machines for making manhole sections, which can be described as very short pipes, it is evident that a machine used for this purpose is operating at a low level of output and is being uneconomically used.
The object of the invention is to provide a method of making short lengths of pipe on a vertical pipe-making machine which materially increases the productivity of the machine, to the extent that the economic advantage of the machine in the manufacture of long pipes is to a considerable extent preserved.